Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> writes: > On Sat, Dec 01, 2018 at 08:34:06AM +0800, Huang, Ying wrote: >> Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> writes: >> > What do you think? >> >> I think that swapoff() which is the main user of try_to_unuse() isn't a >> common operation in practical. So it's not necessary to make it more >> complex for this. > > Ok, probably not worth the surgery on try_to_unuse, even if swapoff can be > expensive when it does happen. > >> In alloc_hugepage_direct_gfpmask(), the only information provided by vma >> is: vma->flags & VM_HUGEPAGE. Because we have no vma available, I think >> it is OK to just assume that the flag is cleared. That is, rely on >> system-wide THP settings only. >> >> What do you think about this proposal? > > Sounds like a good compromise. > > So alloc_hugepage_direct_gfpmask will learn to make 'vma' optional? Slightly > concerned that future callers that should be passing vma's might not and open a > way to ignore vma huge page hints, but probably not a big deal in practice. alloc_pages_vma() -> get_vma_policy() -> __get_vma_policy() has done that already. So I guess that's not a big issue. The callers should be careful. Best Regards, Huang, Ying
